clk: bcm: rpi: Make sure the clkdev lookup is removed

The clkdev lookup created for the cpufreq device is never removed if
there's an issue later in probe or at module removal time.

Let's convert to the managed variant of the clk_hw_register_clkdev function
to make sure it happens.

Cc: Michael Turquette <mturquette@baylibre.com>
Cc: linux-clk@vger.kernel.org
Acked-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/075e2c6d315eccdaf8fb72b320712b86e6c25b22.1592210452.git-series.maxime@cerno.tech


Signed-off-by: Stephen Boyd <sboyd@kernel.org>